Airhead Tech Pages

Spline lube for R100GS

Becasue of a transmission failure I dissassembled my GS at about
45K miles. Here's what I learned. Having neither the special tools or the knowhow
to rebuild the transmission, I took it to Paul Swenson of Colorado Springs.
The failure was the front
output shaft bearing. On dissasembly of the bike I aslo determined the rear
u-joint was notchy in one plane, so off to Neff (Eurotech's rebuilder) it went.
At Paul's suggestion I removed the clutch disk and cleaned everything thouroughly,
especially the spline which was quite dry, even though it was lubed the previous
year.

Here are some tips.

1. Make 6 headless studs 40-50 cm long in order to put the clutch
back together. Without them it's a three handed job, at best, even with the
special disk alignment tool. 6mm X1.25 pitch.

2. Make 2 headless studs 8mmX1.5pitch, again at least 40-50cm
long in order to slide the trannie back without hanging it on the spline. Bolts
can be used here per previous articles.

Much of the dissasembly and reassembly procedure have been covered previoulsy
by Bob Paskar and Ron Miller , so I will not
comment except where I deviated from thier procedures. These notes apply to
the late model with the large hole pressure plate. This is not the type shown
in my Haynes and Clymer manuals. The proper grease is no longer Starburgs,
but BMW #10.

You should remove the clutch assembly and clean the spline thoroughly.
Lube sparingly, the contact points where the spring rides in the flywheel (the
entire outer circumference), the points where the springs contacts the front
of the pressure plate, the clutch plate spline, center bushing in the flywheel,
as well as the center bushing in the spring. I also lubed the tip of each spring
finger.

Clean and sparingly lube the transmission input splines, a toothbrush
works well here, making sure to lightly coat all surfaces of each spline.

Clean and lube the throwout bearing. Using the tube of BMW #10,
I squeezed grease into the throwout bearing, then put the end of the throwout
rod in to pack it in, and repeat until clean grease comes out around the edges.
Paul tells me this is a $90 part, don't neglect it. It's very easy to
get at, even between spline lubes.

Grease the bearing in the pivot point of the clutch lever. The
sleeve will come out, but be careful not to drop the needles. I pushed the
sleeve out halfway, pack one side, then push it thorough to the other side
and repeat. If it won't turn, replace it. This is the time to renew the speedo
cable boot if needed, as water gets in here. Some silicon gease around the
cable where the boot seals will help here. If you removed it, you must grease,
lightly, and return the throwout rod to the transmission BEFORE you put the
swing arm in. Ask me how I know.

Also, Put the wires back on the neutral light switch before you
slide the transmission home. Rear drive and driveshaft. Like a number of others,
I had to file the driveshaft housing to get the rebuilt shaft in. I bought
a section of 1 inch 60 grit sanding belt, and used it inside the housing like
a polishing rag. This will get junk in the bearings if you are not careful.
Some instructions said not to repack the bearings, as the shaft breathes through
them, my studs had holes all the way through, so I repacked the bearings.

You cannot grease these bearings, like the ones on a monolever
because there is no backing plate behind the bearing. I found an EASY way to
reassemble the rear spline and rear drive, I did it on the bench, but it could
be done on the bike if you understand the concept.. Put the rear drive
in a 6 quart oil box, to keep it from rolling around. Push the driveshaft as
far into the housing as possible so the rear yoke is accessable. Align the
driveshaft housing to the rear drive at a 45 degree angle, toward the brake
shoe side. You will be able to put the splined yoke on the rear drive with
your fingers. Then you can rotate the
housing untill the bearing studs can be inserted. From this point on, keep
the driveshaft end up, or it will slide off the splines, ask me how I know
this, too.

Now its is nice to have a floor jack, put the box on the floor
jack and guide the swing arm into place, a friend helps here. An alternative
is to connect the shock and then by manipulating the jack you can get the swing
arm in by yourself. Once the swing arm pivot pins are screwed in you can connect
the paralever torque arm. I always try to connect everything possible before
torqueing anything.